U.S. patent number 6,118,014 [Application Number 09/354,675] was granted by the patent office on 2000-09-12 for organofunctional cocyclic siloxanes.
This patent grant is currently assigned to Dow Corning Corporation. Invention is credited to Daniel Joseph Halloran, Brett Lee Zimmerman.
United States Patent |
6,118,014 |
Halloran , et al. |
September 12, 2000 |
Organofunctional cocyclic siloxanes
Abstract
New compositions of matter are organofunctional cocyclic
siloxanes of the formula ##STR1## where R1 to R3 are alkyl groups
of 1-6 carbon atoms; a and b have a value of 1-10; and R4 is an
aminoalkyl group or a carboxyalkyl group. Some representative R4
groups are --CH.sub.2 CH.sub.2 CH.sub.2 NH.sub.2, --CH.sub.2
CH.sub.2 CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2, --CH.sub.2
CH(CH.sub.3)CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2, and
--(CH.sub.2).sub.10 COOH.
Inventors: |
Halloran; Daniel Joseph
(Midland, MI), Zimmerman; Brett Lee (Birch Run, MI) |
Assignee: |
Dow Corning Corporation
(Midland, MI)
|
Family
ID: |
23394441 |
Appl.
No.: |
09/354,675 |
Filed: |
July 16, 1999 |
Current U.S.
Class: |
556/439; 554/77;
556/425; 556/479 |
Current CPC
Class: |
C07F
7/21 (20130101); C08G 77/44 (20130101); C08G
77/045 (20130101) |
Current International
Class: |
C07F
7/00 (20060101); C07F 7/21 (20060101); C08G
77/04 (20060101); C08G 77/00 (20060101); C08G
77/44 (20060101); C07F 007/08 (); C07F
007/10 () |
Field of
Search: |
;556/439,425,479,77 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Shaver; Paul F.
Attorney, Agent or Firm: De Cesare; James L.
Claims
What is claimed is:
1. A composition of matter comprising a cocyclic siloxane having
the formula ##STR13## where R1 to R3 are each an alkyl group
containing 1-6 carbon atoms; R4 is a carboxyalkyl or carboxyalkyl
derivative group having the formula --(CHR5).sub.n COOR6 where R5
is hydrogen or an alkyl group containing 1-6 carbon atoms; R6 is
hydrogen, an alkyl group containing 1-6 carbon atoms, or a
trialkylsilyl group --Si(R7).sub.3 where R7 is an alkyl group
containing 1-6 carbon atoms; a and b are each a positive integer
having a value of 1-10; and n is a positive integer having a value
of 3-20.
2. A composition according to claim 1 in which R1 to R3 are each
the methyl group.
3. A composition according to claim 1 in which R4 is the
carboxyalkyl group --(CH.sub.2).sub.10 COOH.
4. In a hydrosilation process in which an .tbd.SiH containing
reactant is contacted with a reactant containing unsaturation in
the presence of a Group VIII transition metal catalyst, the
improvement comprising using as the .tbd.SiH containing reactant, a
cocyclic siloxane having the formula ##STR14## where R1 to R3 are
each an alkyl group containing 1-6 carbon atoms, and a and b are
each positive integers having a value of 1-10; the reactant
containing unsaturation being an alkenoic acid or an alkenoic acid
derivative having the formula (H.sub.2 C).sub.m
.dbd.CR5(CR5.sub.2).sub.n COOR6 where R5 is hydrogen or an alkyl
group containing 1-6 carbon atoms; R6 is hydrogen, an alkyl group
containing 1-6 carbon atoms, or a trialkylsilyl group
--Si(R7).sub.3 where R7 is an alkyl group containing 1-6 carbon
atoms; m is a positive integer having a value of 1-3; and n is a
positive integer having a value of 1-20.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
Not applicable.
REFERENCE TO A MICROFICHE APPENDIX
Not applicable.
FIELD OF THE INVENTION
This invention is directed to new compositions of matter, and more
particularly to (i) a dialkyl, alkyl aminoalkyl cocyclic siloxane,
preferably a dimethyl, methyl aminoalkyl cocyclic siloxane, and
(ii) a dialkyl alkyl carboxyalkyl cocyclic siloxane, preferably a
dimethyl, methyl carboxyalkyl cocyclic siloxane. These compositions
are prepared by hydrosilation and are useful as oligomers in the
preparation of other siloxane polymers.
BACKGROUND OF THE INVENTION
While cocyclic siloxanes are generally known in the prior art, the
organofunctional cocyclic siloxanes of the present invention are
not believed to be described in the literature.
For example, U.S. Pat. No. 3,299,112 (Jan. 17, 1967), relates to
certain dimethyl methyl polyether cocyclic siloxanes; U.S. Pat. No.
5,160,494 (Nov. 3, 1992) relates to certain dimethyl methyl higher
alkylmethyl cocyclic siloxanes; and U.S. Pat. No. 5,395,955 (Mar.
7, 1995) relates to certain dimethyl methyl carbinol cocyclic
siloxanes. In addition, U.S. Pat. Nos. 5,160,494 and 5,395,955 also
describe certain dimethyl methyl hydrogen cocyclic siloxanes.
However, none of these patents describe either the (i) dialkyl,
alkyl aminoalkyl cocyclic siloxane, or (ii) the dialkyl, alkyl
carboxyalkyl cocyclic siloxane, of this invention.
BRIEF SUMMARY OF THE INVENTION
The invention relates to a composition of matter, which in one
embodiment, is a cocyclic siloxane having the formula ##STR2##
where R1 to R3 are each an alkyl group containing 1-6 carbon atoms;
a and b are each a positive integer having a value of 1-10; and R4
is an aminoalkyl group having the formula ##STR3## where R'" and
R"" are each hydrogen or an alkyl group containing 1-4 carbon
atoms, R.sup.v is hydrogen or a group having the formula ##STR4##
where c is a positive integer having a value of 2 or 3, and
R.sup.v' and R.sup.v" are hydrogen or an alkyl group containing 1-4
carbon atoms.
Alkyl groups represented by R1, R2, R3, R'", R"", R.sup.v', and
R.sup.v" include methyl, ethyl, propyl, isopropyl, butyl, and
isobutyl.
In this first embodiment, the R4 aminoalkyl groups most preferred
are --CH.sub.2 CH.sub.2 CH.sub.2 NH.sub.2, --CH.sub.2 CH.sub.2
CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2, and --CH.sub.2
CH(CH.sub.3)CH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2.
In another embodiment, the invention relates to a composition of
matter which is a cocyclic siloxane having the formula ##STR5##
where R1 to R3 are each an alkyl group containing 1-6 carbon atoms;
R4 is a carboxyalkyl or carboxyalkyl derivative group having the
formula --(CHR5).sub.n COOR6 where R5 is hydrogen or an alkyl group
containing 1-6 carbon atoms; R6 is hydrogen, an alkyl group
containing 1-6 carbon atoms, or a trialkylsilyl group
--Si(R7).sub.3 in which R7 is an alkyl group containing 1-6 carbon
atoms; a and b are each a positive integer having a value of 1-10;
and n is a positive integer having a value of 3-20.
These and other features of the invention will become apparent from
a consideration of the detailed description.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
Not applicable.
DETAILED DESCRIPTION OF THE INVENTION
Hydrosilation is a known reaction involving the addition of a
silicon hydride to an unsaturated hydrocarbon to form a
silicon-carbon bond. It is used commercially to synthesize
organofunctional silicon monomers, to crosslink silicone polymers,
and to connect a silicone to an organic polymer block to form a
copolymer. One example is the hydrosilation of an alpha-olefin with
a methylhydrogen siloxane, according to the reaction:
When used for crosslinking, such platinum catalyzed hydrosilation
reactions typically involve reaction between a low molecular weight
polysiloxane containing several .tbd.Si--H groups and a high
molecular weight polysiloxane containing several .tbd.Si-vinyl
groups, or vice versa.
Generally, stoichiometric amounts of the .tbd.SiH containing
reactant, and the reactant containing unsaturation, should be
employed in the process. It may be necessary, however, to use an
excess of the reactant containing unsaturation to totally consume
the .tbd.SiH in the siloxane product.
The maximum amount of platinum catalyst employed is determined by
economical considerations, and the minimum amount is determined by
the type and purity of the reactants employed. Generally, very low
concentrations of platinum catalyst, such as 1.times.10.sup.-10
moles catalyst per equivalent of the reactant containing
unsaturation, may be used when the reactants are extremely pure.
However, it is possible to use about 1.times.10.sup.-8 moles
catalyst per equivalent weight of reactant containing unsaturation,
and even 1.times.10.sup.-7 to 1.times.10.sup.-3 moles platinum
catalyst per equivalent weight of reactant containing
unsaturation.
Moles of platinum catalyst are measured in terms of one mole
providing one unit atom (e.g. one gram atom) of platinum. An
equivalent weight of reactant containing unsaturation is the amount
of reactant furnishing one unit weight of ethylenic unsaturation
(i.e. equivalent to one unit weight of .tbd.SiH), regardless of
what other reactive or potentially reactive substitutents may be
present. Thus, an equivalent weight of ethylene is its molecular
weight.
According to this invention, the platinum catalyst should be
present in an
amount sufficient to provide from about 100 to about 200 parts by
weight of platinum per one million parts by weight of the reaction
mixture, i.e., 100-200 ppm.
Conventional wisdom suggest that hydrosilation reactions involving
the addition of a silicon hydride to an unsaturated hydrocarbon
such as an unsaturated amine to form a silicon-carbon bond, should
not be feasible, due to platinum contamination by polar groups such
as the amine. It has been found unexpectedly, however, that
according to this invention, these reactions can be made to proceed
readily when greater than about 100 ppm platinum is used.
The reaction temperature can vary, and optimum temperatures depend
upon the concentration of platinum catalyst and the nature of the
reactants. The reaction can be initiated at a temperature below
room temperature, i.e., 0.degree. C. to -10.degree. C., and is
exothermic once it begins. The temperature should be one at which
the reactants are in a liquid or gaseous state. The maximum
temperature is determined by the stability of the reactants.
Ordinarily, it is best to keep the reaction temperature below about
300.degree. C. Best results with most reactants are obtained by
initiating the reaction at about 80-180.degree. C., and maintaining
the reaction within reasonable limits of this range. The exothermic
nature of the reaction may push the temperature up to
200-250.degree. C. for a short time, however.
The optimum reaction time is a variable depending upon the
reactants, reaction temperature, and platinum catalyst
concentration. Ordinarily, there is no benefit in extending the
contact time of the reactants beyond 16 or 17 hours, but likewise
there is usually no harm, unless an extremely elevated temperature
is employed. With many reactants, a practical quantitative yield of
product can be obtained in 30 minutes or less.
The reaction can be carried out at atmospheric, sub-atmospheric, or
super-atmospheric pressure. Here again, the choice of conditions is
largely a matter of logic, based upon the nature of the reactants,
and the equipment available. Non-volatile reactants are especially
adaptable to being heated at atmospheric pressure with or without a
reflux arrangement. Reactants which are gaseous at ordinary
temperatures are preferably reacted at substantially constant
volume under autogenous or induced pressure. The best results are
obtained by maintaining all reactants in the liquid phase.
As noted above, hydrosilation requires a catalyst to effect the
reaction between the .tbd.SiH containing reactant and the reactant
containing unsaturation. Suitable catalysts are Group VIII
transition metals. Some examples of metal catalysts which can be
used are a platinum catalyst in the form of the reaction product of
chloroplatinic acid and an organosilicon compound containing
terminal aliphatic unsaturation, as described in U.S. Pat. No.
3,419,593 (Dec. 31, 1968). Another suitable catalyst is Karstedt's
catalyst as described in his U.S. Pat. No. 3,715,334 (Feb. 6, 1973)
and U.S. Pat. No. 3,814,730 (Jun. 4, 1974), which is a
platinum-vinylsiloxane substantially free of chemically combined
halogen. Several types of catalysts, including deposited platinum
type catalysts as well as complexed platinum type catalysts, are
described in detail in U.S. Pat. No. 3,923,705 (Dec. 2, 1975). Yet
another suitable catalyst is a platinum-organosiloxane complex
prepared by reacting a platinous halide with an organosiloxane
having 2-4 silicon bonded organic groups containing terminal
olefinic unsaturation, in the presence of a polar organic liquid
which is a partial solvent for the platinous halide, as described
in U.S. Pat. No. 5,175,325 (Dec. 29, 1992). Still another suitable
hydrosilation catalyst is platinum supported on active carbon
particles of a diameter of 1-2 mm, in which the amount of platinum
supported on the active carbon varies from 0.1-5 percent by weight,
based on the weight of the active carbon.
Among such catalysts, the catalyst most preferred according to this
invention is the neutralized complex of platinous chloride and
divinyltetramethyldisiloxane described in U.S. Pat. No.
5,175,325.
The .tbd.SiH containing reactant according to the present invention
is a cocyclic siloxane having the formula ##STR6## where R1 to R3
are each an alkyl group containing 1-6 carbon atoms, and a and b
are each a positive integer having a value of 1-10. Alkyl groups
generally representative of R1, R2, and R3 include methyl, ethyl,
propyl, isopropyl, butyl, isobutyl, pentyl, and hexyl.
Such .tbd.SiH containing cocyclic siloxanes and methods for their
preparation are known in the art, and reference may be had, for
example, to U.S. Pat. No. 5,160,494 (Nov. 3, 1992), and U.S. Pat.
No. 5,395,955 (Mar. 7, 1995).
The .tbd.SiH containing reactant most preferred according to the
present invention is a cocyclic siloxane having the formula
##STR7## where R4 has the same meaning as defined above, a has an
average value of 4, and b has an average value of one.
The reactant containing unsaturation which is used to prepare the
dialkyl, alkyl methyl aminoalkyl cocyclic siloxane by hydrosilation
is an unsaturated amine having the formula ##STR8## where R'" and
R"" are hydrogen or an alkyl group containing 1-4 carbon atoms;
R.sup.v is hydrogen or a group having the formula ##STR9## in which
c is a positive integer having a value of 2 or 3, and R.sup.v' and
R.sup.v" are hydrogen or an alkyl group containing 1-4 carbon
atoms.
Some representative unsaturated amines most preferred for use
herein are allyl amine H.sub.2 C.dbd.CHCH.sub.2 NH.sub.2, the
compound H.sub.2 C.dbd.CHCH.sub.2 NHCH.sub.2 CH.sub.2 NH.sub.2, or
the compound H.sub.2 C.dbd.C(CH.sub.3)CH.sub.2 NHCH.sub.2 CH.sub.2
NH.sub.2.
The reactant containing unsaturation which is used to prepare the
dialkyl, alkyl carboxyalkyl cocyclic siloxane by hydrosilation is
an alkenoic acid, preferably an alkenoic acid which has a melting
point of about 40.degree. C. or less. Some examples of suitable
alkenoic acids which can be used are 3-butenoic acid (vinylacetic
acid) H.sub.2 C.dbd.CHCH.sub.2 COOH, 4-pentenoic acid (allylacetic
acid) H.sub.2 C.dbd.CH(CH.sub.2).sub.2 COOH, trans-2-pentenoic acid
C.sub.2 H.sub.5 CH.dbd.CHCOOH, trans-3-hexenoic acid C.sub.2
H.sub.5 CH.dbd.CHCH.sub.2 COOH, 6-heptenoic acid H.sub.2
C.dbd.CH(CH.sub.2).sub.4 COOH, and 10-undecenoic acid (undecylenic
acid) H.sub.2 C.dbd.CH(CH.sub.2).sub.8 COOH.
If desired, the alkenoic acid can be used in the hydrosilation
reaction in an esterified form. Alternatively, and optionally, the
alkenoic acid can be protected/silylated. Thus, it may be desirable
to protect the hydroxyl group --OH of the alkenoic acid in order to
prevent undesired reactions during reactions on other parts of the
molecule in the hydrosilation reaction. Following hydrosilation,
the protecting group can be removed.
A number of reagents have been developed for protecting and for
removing such groups. For example, trimethylsilyl protecting
groups, i.e., (CH.sub.3).sub.3 Si--, can be provided by reaction of
the alkenoic acid with a silylating reagent such as
hexamethyldisilazane, i.e., (CH.sub.3).sub.3
SiNHSi(CH.sub.3).sub.3, or trimethylchlorosilane, i.e.,
(CH.sub.3).sub.3 SiCl.
Following the main hydrosilation reaction, the trimethylsilyl
protecting group can be removed by contacting the product of
hydrosilation with a desilylating reagent such as an alcohol,
typically, an alcohol such as methanol, ethanol, or isopropanol.
These protecting/deprotecting steps may require the presence of a
solvent, among which can be used aromatic hydrocarbons such as
toluene, benzene, and xylene, or ethers such as diethyl ether and
tetrahydrofuran. The solvent and any reaction product formed during
these optional protecting/deprotecting steps can be removed in
order to obtain the desired product.
In view of the above, the reactant containing unsaturation can be
best described as an alkenoic acid or an alkenoic acid derivative
having the general formula (H2C).sub.m .dbd.CR5(CR5.sub.2).sub.n
COOR6 where R5 is hydrogen or an alkyl group containing 1-6 carbon
atoms; R6 is hydrogen, an alkyl group containing 1-6 carbon atoms,
or a trialkylsilyl group --Si(R7).sub.3 where R7 is an alkyl group
containing 1-6 carbon atoms; m is a positive integer having a value
of 1-3; and n is a positive integer having a value of 1-20.
EXAMPLES
The following examples are set forth in order to illustrate this
invention in more detail. In these examples, the catalyst was a
neutralized complex of platinous chloride and
divinyltetramethyldisiloxane generally as described in U.S. Pat.
No. 5,175,325. The .tbd.SiH containing reactant was a cocyclic
siloxane having the formula ##STR10## where a had an average value
of 4 and b had an average value of one. The reactant containing
unsaturation was allylamine.
Example 1-3
General Procedure
Into a reaction flask was placed the .tbd.SiH containing cocyclic
siloxane and the platinum catalyst. The reaction flask was purged
with nitrogen, and the allylamine was added dropwise to the flask
to control the evolution of heat. After the addition, the reaction
flask was heated to a temperature in the range of about
80-100.degree. C. Heating was continued, and the temperature of the
reaction flask was maintained for about 6-24 hours. The reaction
flask was cooled to room temperature, and the level of any
unreacted .tbd.SiH was measured using infrared spectroscopy. This
determination was followed by analysis of the product of the
hydrosilation reaction by means of gas chromatography and mass
spectrometry. The various parameters of these examples are set
forth in Table 1.
TABLE 1 ______________________________________ Examples 1 to 3
Parameter Example 1 Example 2 Example 3
______________________________________ Amount of .tbd.SiH Cocyclic
84.6 84.6 84.6 Siloxane (gram) Amount of Allylamine (gram) 85.0
17.1 17.1 Molar Ratio .tbd.SiH Cocyclic 1:5 1:1 1:1
Siloxane/Allylamine Parts per million Platinum 200 200 200 Reaction
Time (hours) 24 6 6 Reaction Temperature (.degree. C.) 100 80 80
Results: Gas Chromatography/ D.sup.R4 D.sub.3 D.sup.R4 D.sub.3 and
D.sup.R4 D.sub.3 and Mass Spectrometry D.sup.R4 D.sub.4 D.sup.R4
D.sub.4 Parts per million .tbd.SiH via 0 0 2.3 Infrared
Spectroscopy ______________________________________
The products prepared by hydrosilation in Examples 1-3, i.e.,
D.sup.R4 D.sub.3 and D.sup.R4 D.sub.4, have the structure shown
below wherein R4 was the group --CH.sub.2 CH.sub.2 CH.sub.2
NH.sub.2, b had a value of one, and a had values of 3 and 4,
respectively. ##STR11##
Example 4A
Silylation/Protection of Undecylenic Acid
Into a reaction flask was placed 276.4 gram of undecylenic acid and
196.8 gram of toluene which was used as a solvent. The reaction
flask was purged with nitrogen, and then 120.8 gram of
hexamethyldisilazane which was used as the silylation reagent, was
added dropwise to the flask. The reaction flask was heated to a
temperature of about 110.degree. C. Heating was continued, and the
temperature of the reaction flask was maintained for about 3 hours.
The toluene solvent was removed by reducing the pressure in the
reaction flask. The reaction flask containing the silylated
alkenoic acid was cooled to room temperature, and the extent of the
reaction to insure completion was determined by infrared
spectroscopy. Analysis by gas chromatography, C.sub.13 nuclear
magnetic resonance (NMR), and mass spectrometry confirmed that the
product was trimethylsilylundecylate, i.e., H.sub.2
C.dbd.CH(CH.sub.2).sub.8 COOSi(CH.sub.3).sub.3.
Example 4B
General Procedure
Into a reaction flask was placed 48.5 gram of
trimethylsilylundecylate prepared in Example 4A and 50 parts per
million of platinum catalyst. The reaction flask was purged with
nitrogen, and then 85 gram of the .tbd.SiH containing cocyclic
siloxane was added dropwise to the flask. The molar ratio of
.tbd.SiH containing cocyclic siloxane to trimethylsilylundecylate
was 1:1. The reaction flask was heated to a temperature of about
110.degree. C. Heating was continued, and the temperature of the
reaction flask was maintained for about 3 hours. The reaction flask
was cooled to room temperature. The level of unreacted .tbd.SiH was
measured using infrared spectroscopy, and determined to be zero
parts per million residual .tbd.SiH. Analysis of the product by
means of gas chromatography and mass spectrometry confirmed that a
silylated dimethyl methyl carboxyfunctional cocyclic siloxane had
been prepared.
Example 4C
Preparation of Carboxyalkyl Cocyclic Siloxane/Removal of Protecting
Group
Into a reaction flask were placed 90 gram of the silylated dimethyl
methyl carboxyfunctional cocyclic siloxane prepared in Example 4B,
and 30 gram of methanol which was used as the desilylating reagent.
The reaction flask was purged with nitrogen, and then the reaction
flask was heated to a temperature of about 110.degree. C. Heating
was continued, and the temperature of the reaction flask was
maintained for about 3 hours. The methanol desilylating reagent and
by-product were removed by reducing the pressure in the heated
reaction flask. The by-product was trimethylmethoxysilane, i.e.,
(CH.sub.3 O)Si(CH.sub.3).sub.3, which was formed as a result of the
reaction between the desilylating reagent and the silylated
dimethyl methyl carboxyfunctional cocyclic siloxane. The reaction
flask containing the desired product, i.e., the desilylated
dimethyl methyl carboxyalkyl cocyclic siloxane, was cooled to room
temperature. Analysis of the product by means of gas chromatography
and mass spectrometry confirmed that it consisted of a mixture of
D.sup.R4 D.sub.4 and D.sup.R4 D.sub.5, having the structure shown
below, where R4 was the group --(CH.sub.2).sub.10 COOH, b had a
value of one, and a had values of 4 and 5, respectively.
##STR12##
Other variations may be made in compounds, compositions, and
methods described without departing from the essential features of
the invention. The embodiments illustrated are exemplary only and
not intended as limitations on their scope except as defined in the
claims.
* * * * *